Apparatus and method for trocar surgical procedure

ABSTRACT

A surgical method involving a trocar system comprising a rack apparatus and a trocar device is disclosed. The trocar device is adapted for insertion into a body cavity, such as the abdominal cavity, using the rack apparatus which eliminates the need for cavity insufflation. The rack apparatus comprises a movable member which attaches adhesively to the external skin surface of the body wall overlying the body cavity. Means are provided moving the member attached to the skin away from the body cavity in order to lift the abdominal region and create a separation between the body wall and the underlying internal organs. This separation permits the obdurator portion of a trocar device to be inserted with a minimum risk of cutting any internal organs. The trocar device comprises applicator and trocar components. The trocar components comprises a cylindrical trocar tube and detachable obdurator. The applicator comprises a housing into which the trocar and obdurator are loaded prior to insertion, and means for applying a force, such as a spring or electric motor, to drive the obdurator and trocar through the body wall into the cavity. Various electrical and mechanical means are provided for limiting the penetration depth of the obdurator.

This application is a Div. of U.S. patent application Ser. No.08/142,192, filed Oct. 22, 1993, now U.S. Pat. No. 5,472,427.

TECHNICAL FIELD

The field of this invention is surgical instrumentation for maintainingthe abdominal wall away from the abdominal viscera.

BACKGROUND

Trocars are sharp instruments used to puncture and maintain an openinginto a body cavity. For example, the opening may be needed for drainingfluids, or to provide access for surgical instruments during endoscopicprocedures. Conventional gas-type trocars are used in conjunction with aprocedure involving insufflation of the body cavity wherein a cannula isinserted into the body cavity through a small incision and the cavityinflated with gas passed through the cannula. The cannula is removed,and an obdurator housed within the bore of a trocar tube is thrust intothe inflated cavity. The obdurator is then removed and an instrument isinserted into the abdominal cavity through the trocar tube. A trocar ofthis conventional type has a valve to maintain the inflated condition ofthe cavity. This need for a valve is problematic because the trocarvalve is an expensive component of the conventional trocar. The need fora valve may also restrict the types of surgical instruments that can beinserted through the trocar. It is of interest to provide improvedapparatus and methods for carrying out the insufflation process andtrocar manipulation.

SUMMARY OF THE INVENTION

The present invention provides a trocar system, including a simplegas-valve-free trocar device, and a surgical rack system and methods forusing them.

Accordingly, one aspect of the invention is a trocar device comprising atrocar applicator, and a trocar tube and obdurator assembly. Theobdurator is removably joined to the tube and has a piercing tip whichextends from the front end of the elongate tube. The tube and obduratorassembly is enclosed by the applicator and is triggered to move betweena normally retracted position in which the obdurator tip is protectedand an extended position in which the obdurator tip is exposed. Forcemeans in the applicator is coupled to the trocar so that the tube andassociated obdurator are driven into the body cavity when the forcemeans is triggered. Adjustable penetration depth limiting means isprovided to limit the penetration depth of the obdurator.

In another aspect, a rack system is provided for opening a void spacewithin the cavity without conventional gas insufflation so that agas-valve-free trocar may be driven into the cavity while controllingthe trocar movement to avoid cutting internal organs. This capability isprovided by cross-beams extending over the skin which overlays thecavity, and which are adjustably attached to a horizontal rack.Attaching means for attaching to the skin are provided and are mountedto the cross-beams. An adherent tape is interposed between the attachingmeans and the skin to adhere them to each other. Lifting hooks mayoptionally be used to engage internal surfaces of the abdominal cavityto aid in opening the void space.

The horizontal rack is coupled to a vertical supporting means whichprovides movement relative to a platform which supports the patient.Moving the cross beams in synchronous movement up from the abdomenraises the abdominal wall away from the viscera so that when the trocarpierces the abdominal wall, it does not cut the viscera. Means areprovided for one or more trocars to be securely attached to thecross-beams; the abdominal wall tissue and trocars are held in alignmentby the cross beams.

DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an embodiment of a trocar device and trocar rack apparatus.

FIG. 2 shows additional detail of portions of the embodiment in FIG. 1and the relationship of the components to a patient undergoing asurgical procedure.

FIG. 3 shows an L-shaped lifting rod in its linear pre-insertionconfiguration.

FIG. 4 shows the L-shaped lifting rod in FIG. 4 in its non-linearpost-insertion configuration.

FIG. 5 shows an exemplary mechanical mechanism, somewhat schematic, fortransforming between the linear and non-linear lifting rodconfigurations shown in FIG. 3 and FIG. 4.

FIG. 6 shows a simple embodiment of a trocar device with the obduratorin its normally retracted position.

FIG. 7 shows the embodiment in FIG. 6 with the obdurator in its extendedposition.

FIG. 8 shows the trocar applicator alone of the trocar device shown inFIG. 6.

FIG. 9 shows the trocar tube and obdurator alone of the trocar deviceshown in FIG. 6.

FIG. 10 shows a sectional view of the trocar tube and obdurator of thetrocar device shown in FIG. 6.

FIG. 11 shows an embodiment of a split housing for a trocar applicator.

FIG. 12 shows an embodiment of a trocar device with the slip-ring depthpenetration limiting means adjusted for slight penetration into theabdominal wall.

FIG. 13 shows the embodiment of a trocar device in FIG. 12 with theslip-ring depth penetration limiting means adjusted for maximumpenetration into the abdominal wall.

FIG. 14 shows an alternative embodiment of a trocar applicator.

FIG. 15 shows an alternative embodiment of a trocar tube and obduratorhaving a fixed penetration depth for use with the trocar applicatorshown in FIG. 14.

FIG. 16 shows an alternative embodiment of a trocar tube and obduratorhaving a fixed penetration depth less than that of the trocar shown inFIG. 15.

FIG. 17 shows an alternative embodiment of a trocar tube and obduratorhaving an adjustable penetration depth for use with the trocarapplicator shown in FIG. 14.

FIG. 18 shows an alternative embodiment of a trocar device having anelectric motor to drive the trocar.

FIG. 19 shows a partial sectional view of the embodiment in FIG. 18.

FIG. 20 is a graph, somewhat schematic, showing the change in expectedsonic wave reflectance at a tissue-cavity boundary.

FIG. 21 shows an embodiment of a trocar obdurator assembly having asonic transceiver to detect penetration of the abdominal cavity.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

The drawings illustrate a trocar system 21 comprising two primarycomponents: a gas-valve-free trocar apparatus 22 and trocar rackapparatus 23 for using the valve-free trocar in surgical procedures.Rack apparatus 23 is used cooper-atively with trocar apparatus 22 tofacilitate safe insertion of trocar 22 without insufflation of the bodycavity.

FIGS. 1-2 are illustrations of an embodiment of trocar mounting rackapparatus 23 for lifting abdominal wall 24 away from abdominal viscera26 of a patient 27 during surgery without using gas insufflation of theabdominal cavity 28. It will be understood that the devices and methodsare not limited to abdominal cavity 28 but may be applied in surgicalprocedures involving other body cavities and other internal bodystructures or internal organs. Selected elements shown in FIG. 1 areillustrated with greater detail in FIG. 2.

Trocar rack apparatus 23 comprises a horizontal rack 29, spaced aparthorizontal cross-beams 31 supported by rack 29, and vertical supportingmeans for raising and lowering rack 29 with synchronous movement ofcross-beams 31, and attaching means for attaching abdominal wall 24 tocross-beams 31.

Vertical supporting means is provided by two vertical cylindrical beamassemblies 32 in the illustrated embodiment, which are attached tohorizontal rack 29 proximal to the upper end of vertical beam assemblies32. Vertical beam assemblies 32 each comprise nesting inner 33 and outer34 cylindrical sections adapted to slide with respect to one another.Vertical motive force means, such as one or more electric motors coupledto a threaded post for elevation upon turning, or alternately a rack andpinion type linear motion system, or a suitably connected hydraulicsystem 36 may be used to synchronously raise or lower inner section 33connected to horizontal rack 29. Manual means, such as a crank, may alsobe used. Alternatively, means for raising and lowering cross beams 31relative to rack 29, may be provided. It will be understood that variousstructures as are known in the mechanical arts may be used to implementrack 29, vertical supporting means, and cross beams 31, and that theinvention is not limited to the particular structures shown.

Attaching means is provided for attaching cross beams 31 to patient 27.For example, an attaching arm 37 is adapted at one end 38 to mount tocross-beam 31 and extends to a second end 39 having a surface adapted toadhere to tape surface 41 adhered to skin 42 of patient 27. An attachingclamp 35 to grasp skin 42 may alternatively be used. The type and numberof attaching arms 37 may depend on the surgical procedure and thecharacteristics of the patient, particularly the size of the abdominalregion 44 (e.g. child or adult) and the weight of the abdominal wall 21to be lifted, including the amount of fat present.

Raising cross-beams 31 causes attaching arm 37 and therefore skin 42,abdominal wall 24 including the parietal peritoneum 43 which lines theabdominal wall, and the visceral peritoneum 45 which lines the abdominalviscera, to raise away from internal abdominal viscera 26. Cross beams31 may be fixed on rack 29 or may be adjustably mounted.

In the illustrated embodiment, horizontal rack 29 comprises cylindricalmembers; however, members having other geometrical forms may be used.Similarly, cross-beams 31 are shown as cylindrical beams which areattached via clamps 46 to rack 29 and which extend over the abdominalregion 44 where the trocar is inserted, but beams having othergeometrical forms, e.g. square, may be used. Preferably at least twocross-beams 31 are used, however more beams or even a single beam may beused; the number depending on the nature of the surgical procedure. Asingle cross beam 31 may be used if attaching arm 37 mounted to crossbeam 31 comprises an elongated structure adapted to extend from crossbeam 31 to separated regions of the abdomen 44, or alternatively ifcross beam 31 in aligned longitudinally with patient 27.

Trocar rack apparatus 23 may further include one or more trocar mountingmeans attached to cross-beam 31 for mounting trocar tube 47 in a stableupright position, with or without a surgical instrument (not shown)inserted. Various trocar mounting means are suitable including clamps,ties, clips, collars, and the like. For example, trocar mounting meansmay comprise an adjustable trocar mounting arm or clamp 51 adapted atone end for mounting to cross beam 31 and having a cylindrical collar 52at the other end, that can be tightened around a cylindrical trocar tube47. A pivot 53 may be provided between the two ends of clamp 51 topermit precise positioning of clamp 51 to trocar 47 when inserted intoabdominal cavity 28. Trocar tube 47 may be provided with structure onits external surface to couple to clamp 51. For example, a depression ornotch 54 on the external cylindrical surface of trocar tube 47 may beprovided that engages a spring loaded plunger (not shown) within theinternal cylindrical collar 52 of clamp 51 to positively lock trocartube 47 to clamp 51. Trocar tube 47 may optionally have a greater lengththan a conventional trocar to facilitate attachment to cross-beam 31.

Trocar rack apparatus 23 may also optionally include supporting platform48. In the embodiment illustrated in FIGS. 1-2, vertical cylindricalbeam assemblies 32 are connected to supporting platform 48. Supportingplatform 48 may be a platform as shown, or other type of structure suchas a floor surface, or an operating table or portion thereof.

Lifting hooks, such as L-shaped rods 50 may optionally be used to engageinternal surfaces of the abdominal cavity, such as the abdominal wall24, to lift and/or support the abdominal wall and thereby assist inopening and/or maintaining the void space in the abdominal cavity asshown in FIG. 2. The optional use of lifting hooks is of benefit whenthere is an expectation that the viscera will adhere to the abdominalwall structure or where the weight of the abdominal wall suggests thatsupport in addition to that provided by the tape surface 41 or attachingclamp 35 is of benefit.

The structure of an exemplary L-shaped rod having alternate straight(linear) and L-shaped (non-linear) conformations is illustrated in FIGS.3 and 4. FIG. 3 illustrates L-shaped rod 50 in its linear configuration(e.g. non-"L-shaped") as it would appear during insertion into apatient, and after removal from the patient. FIG. 4 illustrates theL-shaped rod in non-linear (e.g. L-shaped") configuration as it wouldappear after insertion while supporting the abdominal wall of a patient.The structure of the rod permits it to be easily inserted into apatient, and to transform between the straight and L-shapedconfigurations as described hereinafter.

L-shaped rod 50 comprises hollow outer shaft 55, extension 56, pivotdowel 57 which rotatably couples outer shaft 55 to extension 56,adjustment knob 58, and partially threaded internal pin 59. Each elementof rod 50 is preferably made of a noncorrosable and sterilizablematerial, such as stainless steel, or the like. Extension 56 ispivotally coupled to one end of shaft 55 via pivot dowel 57 at a pivotpoint 60. The pivot point is located between between the two ends ofextension 56 to provide the desired fulcrum and mechanical leverage, andto preserve a small cross-sectional area in the region of the pivot sothat rod 50 is more easily inserted. Knob 58 is rotatably attached tothe other end of shaft 55, and has a threaded hole 61 through its centerthat engages threads on internal pin 59. Rotation of knob 58 causes pin59 to move longitudinally within the hollow bore of shaft 55. The lengthof pin 59 and the location of the pivot point on extension 56 areselected so that as knob 58 is rotated, pin 59 moves along shaft 55 toengage one side of extension 56. Extension 56 undergoes an angularrotation relative to shaft 55 as pin 59 is translated due to thelevering action of the pivot as shown in FIG. 5.

The overall length of extension 56 and the position of the pivot pointrelative to its two ends allows the desired 90 degree rotation of theextension to be accomplished with only a short linear translation of pin59. The long side of extension 56 is pointed or tapered, such as in theform of a blade or a lance to facilitate insertion through the skin andabdominal wall. While one mechanism for affecting an L-shape to theinitially linear rod has been described, other mechanical mechanisms ormeans for providing the L-shape after insertion may be used withcomparable effectiveness, including other means for coupling andadjusting the angle between the shaft and the extension, and shapesother than the "L-shape". For example, a lifting hook having multipleL-shaped extensions may be used, such as a T-shape, a fan shape, and thelike.

During surgery, the L-shaped rods are adjustably mounted on cross-beams31 and extend vertically downward from cross-beams 31 toward patient 27.The L-shaped rods are inserted through surgical incisions into abdominalcavity 28 and provide greater lifting and/or holding ability thanattaching arm 37 may provide alone. Each L-shaped rod may be used inconjunction with a sterile adhesive tape 40 to provide a sterile surfaceregion on the skin surrounding the rod insertion site. The tape surfaces40 may be covered with a pealable layer, such as a sterile polymeric orfoil type layer, to preserve sterility. When an L-shaped rod is usedwith attaching arm 37, adhesive tape 40 may be integral with tapesurface 41 interposed between second end 39 of attaching arm 37 and theskin. After insertion of the L-shaped rods and attachment of theattaching arms 37 to the skin, cross-beams 31 are raised, causingL-shaped rods, which extend under parietal peritoneum 43 and optionallyunder visceral peritoneum 45, to lift and separate the abdominal wallfrom viscera 26. Alternately, the L-shaped rods may be used alone with aseparate adhesive tape surface to effect and maintain separation beforeand during surgery.

FIGS. 6-7 are illustrations of an embodiment of a gas-valve-free trocardevice 22 in accordance with one aspect of the invention. Trocar device22 comprises separable trocar applicator 62 and trocar assembly 63.Trocar assembly 63 comprises trocar tube 47 and obdurator 64. FIG. 6shows trocar 22 with obdurator 64 in its normally retracted position.FIG. 7 shows trocar 22 with obdurator 64 extended.

FIG. 8 shows applicator 62 without trocar/obdurator assembly 63installed. Applicator 62 is used for inserting trocar tube 47 andobdurator 64 into abdominal cavity 28 and comprises housing 65, forcemeans such as spring 66, trigger means such as trigger 67, and trocarpenetration limiting means 70.

Housing 65 comprises a lower pad 69 and a vertical frame 71 mounted onpad 69. Pad 69 is a disc-like plate having an orifice 72 through whichtrocar 47 can extend during insertion. The relatively large disc-likesurface of pad 69 facilitates placement against patient 27 withoutentering the patient, and further orients trocar tube 47 for orthogonalpenetration. Vertical frame 71 may comprise two (or more) verticallyextending members 73 as shown, or comprise a enclosing column 74 asshown in FIG. 11, for example. Pad 69 is placed in contact with skin 42at the insertion location. Preferably, one or more optional layers 76may be provided on the skin contact surface of lower pad 69, such as apuncturable cover seal 77, and sterile pads 78, for example. The entiretrocar tube 47 may be sealed within a sterile enclosing trocarapplicator 63 which completely surrounds trocar tube 47 to maintain thesterility of pad 69, obdurator 64, trocar tube 47, and other elementsprior to use.

Pad 69 and vertical frame 71 may be formed as an integral unit. FIG. 11is an illustration of a trocar applicator 62 in which each of lower pad69 and vertical enclosing column 74 are integral but comprise twoseparable sections 79, 81 adapted for easily attaching and removingtrocar tube 47. A hinge 82 is provided so that the two halves of housing65 can be easily opened to insert or remove trocar 47. A locking clip 85is provided to secure the two haves of housing 65. Hinge 82 alsofacilitates adjustment of the trocar penetration depth as describedbelow. Hinge 82 may be a separate conventional two part mechanical hingeor may be a structure formed into a molded plastic housing 65, such as athinned wall region that facilitates bending.

In reference to FIGS. 6-10, spring 66 is provided for drivingtrocar-obdurator 63 through abdominal wall 24 and is mounted to, orretained within, vertical frame 71 of housing 65. Trigger 67 is formaintaining spring 66 in a deactivated or compressed condition whenobdurator 64 is in its normally retracted position within applicatorhousing 65, and for activating or releasing spring 66 to drive trocar 47into an exposed position capable of penetrating abdominal wall 24.

Trocar penetration limiting means is provided for limiting the distancetrocar obdurator assembly 63 is driven (or penetrates) through abdominalwall 24, and may generally be located on vertical frame 71. Penetrationlimiting means permits safe insertion of trocar tube 47. Oncetrocar-obdurator assembly 63 has been driven into abdominal wall 24,additional penetration may be achieved if desired, by manually turningtrocar-obdurator 63 while applying downward pressure. Exemplary detailedattributes of force means, trigger means, and penetration limitingmeans, are now described in the context of exemplary embodiments.

In a first embodiment of a trocar device 22, such as the embodimentillustrated in FIGS. 6-10, the force means comprises spring 66 mountedin the upper portion 83 of vertical frame 71, and trigger meanscomprising spring locking and releasing means for maintaining the springin a compressed position and for releasing the spring upon a triggeringcommand to drive the trocar tube downwardly through the skin andabdominal wall into abdominal cavity 28. In this embodiment, spring 66is compressed and held in compressed condition by trocar tube 47. Pin 84engages a receptacle 86 on the external surface of trocar tube 47 and iscoupled to a pivoted lever 87. When pivoted lever 87 is pressed inwardtoward trocar tube 47, pin 84 is retracted from engaging receptacle 86,thereby releasing trocar tube 47 to move under the force of compressedspring 66.

While a compression-type spring 66 is shown, an extension-type springwith suitably altered attachment points may be used. Spring locking andreleasing means may be other types of mechanical devices known in theart capable of holding spring 66 in a compressed condition and thenreleasing it.

Penetration distance limiting means 70 comprises internal threads 88inside vertical frame 71 spaced apart from and below spring 66 whichcooperates with elements of trocar assembly 63 including slip-ring 91and flange 92, as described below. Threads 88 may be helical screw typethreads or alternatively discontinuous annular grooves or rings. Threads88 have a narrower separation between the two vertical support members73 than the separation between the portions of vertical support members73 between spring 66 and threads 88, so as to form a narrower neck orrestriction 93 in frame 71. A relatively high friction surface mayalternatively be used to lock slip-ring 91 into position within frame71. The operation of coarse threads 88, annular rings or slots 90, orother high friction surface, are described in greater detail following adescription of the trocar and obdurator elements.

FIG. 9 shows an exemplary structure of trocar and obdurator assembly 63for use with trocar applicator 62. The illustrated trocar-obduratorassembly 63 is the same as that illustrated in FIGS. 6-7. Assembly 63comprises a cylindrical trocar tube 47, trocar tube applicatorengagement means for limiting the distance obdurator 64 is driven byspring 66 in applicator 62, obdurator 64, and obdurator locking means 94for releasably locking the obdurator to the tube.

Cylindrical trocar tube 47 is an elongated hollow tube (cannula) havingan inner surface 96 and an outer surface 97. As shown in FIG. 10, innersurface 96 has a locking channel 98 having a bend (approximately 90degrees in this embodiment) which is adapted to removably engage alocking prong 94 on obdurator 64.

Trocar tube applicator engagement means, a flange 92, for limiting thedistance obdurator 64 is driven by spring 66 through the abdominal wall24 is attached to outer surface 97. Flange 92 is integral with the outersurface 97 of trocar tube 47 end extends a greater radial distance fromthe center of tube 47 than does the remainder of tube 47. Flange 92 mayalternately extend around a partial or full circumference of tube 47, orcomprise a single increase in diameter (e.g. a step) over a portion oftube 47, so that trocar tube 47 has a smaller diameter proximateobdurator 64 and a larger diameter distal to obdurator 64.

Flange 92 has a larger outer diameter than the inner diameter ofslip-ring 91, so as to be unable to slide past slip-ring 91. In thisway, the downward thrust of the trocar 47 can be adjustably controlled.Slip-ring 91 is adapted to adjustably engage the threads inside verticalframe 71 for adjusting the penetration distance of the trocar.Spiral-type mating threads provide means for adjusting the location ofthe slip-ring by rotating (screwing) the slip-ring relative to themating threads in the vertical frame. The threads may have a fine orcoarse pitch.

FIGS. 12-13 illustrate the manner in which slip-ring 91 acts as anadjustable stop for limiting the distance trocar 47 is driven by spring66. The penetration distance is selected by locating the split-ring 91within annular rings 90. Placing slip-ring 91 further away from pad 69results in a shallow penetration depth, whereas placing slip-ring 91closer to pad 69 results in a deeper penetration depth. The greater theinitial distance between flange 92 and slip-ring 91, the farther trocar47 can move before flange 92 engages slip-ring 91.

FIG. 12 illustrates the relatively shorter penetration distance oftrocar/obdurator assembly 27 when slip-ring 91 is positioned near thetop of vertical support 71. FIG. 13 illustrates the relatively greaterpenetration distance of trocar-obdurator assembly 63 when slip-ring 91is positioned near the bottom of vertical support 71. FIGS. 12-13 showan embodiment wherein annular rings or slots 90 are provided rather thanspiral screw-type coarse threads 88. In this embodiment, slip-ring 91 isfabricated in a thickness that permits mounting slip-ring 91 betweenneighboring annular rings or slots 90, thereby providing incrementaldistance adjustment.

Hinge 82 facilitates adjustment of penetration depth by allowingslip-ring 91 to be placed at the desired location within annular rings90 of applicator 62, or within coarse threads 88 without requiringsignificant rotational adjustment, to set the penetration depth. Theposition is selected prior to activation of spring 66 so that obdurator64 penetrates only to the desired depth.

Other means for compressing the spring and for maintaining the spring ina compressed condition without the necessity to insert thetrocar-obdurator assembly 63 into the applicator and means for limitingthe distance the trocar-obdurator 64 is driven by spring 66 may beprovided. For example, in the embodiment illustrated in FIG. 14, differsin two ways from the embodiment illustrated in FIGS. 6-10.

In the embodiment illustrated in FIG. 14, a separate spring controlmeans is provided for compressing the spring and for maintaining thespring in a compressed condition without the necessity to insert thetrocar-obdurator assembly 63 into the applicator. Spring 66 iscompressed and held in compressed condition by a retaining disk 95. Pin84 engages a notch 100 on the external surface of retaining disk 95 andis coupled to a pivoted lever 87. When pivoted lever 87 is pressedinward toward the applicator housing, pin 84 is retracted from the notch100. When a trocar tube 47 is inserted into the applicator, spring 66extends to press disk 95 into contact with the upper end of the trocartube, thereby moving trocar tube 47 under the force of spring 66. Thisstructure permits the spring to be compressed prior to insertion of thetrocar-obdurator assembly.

The embodiment in FIG. 14 also has an annular half-ring 101 formedintegral to each vertical support member 73 at a fixed position.Half-rings 101 are employed, rather than a single continuous ring sothat the two halves of the applicator housing can be opened at hinge 82,facilitating placement of the trocar prior to insertion and subsequentremoval of the applicator from the inserted trocar. In this embodiment,trocar tube 47 has an enlarged flange 102 as illustrated in FIG. 12,which engages fixed half-rings 101 to limit the penetration depth of thetrocar-obdurator into the abdominal wall. In the embodiment illustratedin FIG. 12, flange 102 is formed integral with the outside wall of thetrocar at a predetermined position from the obdurator tip. As shown inFIGS. 15-16, trocar tubes having the flange at different locations maybe selected at the time of trocar insertion to provide the desiredpenetration. For example, different trocar tubes may be fabricatedhaving flange 102 located in 5-10 mm increments. Alternatively, anotherembodiment, such as that shown in FIG. 17 has a separate non-integralannular flange 102 having internal spiral threads (not shown) which mateto spiral threads 103 on the outside surface of trocar tube 47. Thepenetration distance is set by rotating flange 102 on the mating spiralthreads to position the flange at a suitable distance from the obduratortip. The spiral threads on the exterior surface of the trocar tubeshould have a sufficiently fine pitch so that the threads do not overlyrestrict the smooth entry of the trocar tube into the abdominal wall.

Obdurator 64 has a generally cylindrical shape to conform to theinternal surface of trocar tube 47 through which a portion of obdurator64 extends. Obdurator has a sharp tip 105 capable of piercing abdominalwall 24. Sharp tip 105 extends past the front end 104 of tube 47 so thatwhen applicator 62 drives trocar/obdurator assembly 63 forward, sharptip 105 penetrates abdominal wall 24 first. A relative rapid drivingforce is required for proper penetration of obdurator 64 into abdominalwall 24. Slow penetration may undesirably compress the abdominal regionrather than puncture it. The obdurator has a shape and size that permitsit to be removed from the trocar tube after penetration of the abdominalwall by passing it back through the tube without removal the tube fromthe abdomen.

Obdurator locking means such as locking prong 94 is provided forremovably locking obdurator 64 into position in tube 47. Prong 94engages locking channel 98 on the inside surface of cylindrical tube 47.A handle 104 is provided for removing obdurator 64 from inside tube 47after penetration. The handle should have a surface to facilitategrasping and hand turning and extend from the end of the trocar tubewhen inserted. The handle may be inserted after applicator 43 has beenremoved from the trocar-obdurator assembly. Handle 107 may be formedintegral with obdurator 64 or be a detachable element which engages aslot within obdurator 64 permitting rotation of prong 94 out of channel98 so that obdurator 64 may be lifted out of the interior of trocar tube47.

FIG. 18 illustrates the structure of a more sophisticated embodiment oftrocar apparatus 22, In this embodiment force means comprises anelectric motor 111 Coupled to a traction wheel 112 for applying atractional force to drive trocar/obdurator assembly 63 into and throughabdominal wall 24. Traction wheel 112 may be a cylindrical wheel with arelatively high friction surface or may have gear teeth 113 on itscircumferential surface 114. Trocar tube 47 has cooperating structure toengage wheel 112 including gear teeth 113 such as a toothed linear track116.

In this embodiment, first electrical switch 117 is provided fortriggering motor 111 to begin driving trocar-obdurator assembly 63.Second electric switch 118 is provided for limiting the penetrationdepth of the driven trocar 63. A single switch may be used for startingad stopping driving of the obdurator; however, switches 117 and 118 arepreferably different switches connected in electrical series so thatboth switches must be on for power to be delivered to motor 111. Theprovision of second switch 118 allows the penetration depth to be setbefore starting to drive the obdurator so that the obdurator isautomatically stopped at the desired penetration depth, therebyeliminating risk the obdurator will be driven too deeply by a manuallycontrolled stop switch. Second switch 118 may be a small switch, e.g. amicro-switch, adjustably mounted on applicator 62.

A switch button engagement structure, such as a raised strip 119 on theexternal surface of trocar tube 47 slidably engages a switch button 121on switch 118 to maintain switch 118 in an on condition. When switchbutton 121 travels far enough to move past the raised strip, button 121disengages raised strip 119, and switch 118 is turned off. The locationof raised strip 119 or alternatively of switch button 121 to adjust thepenetration depth of the trocar assembly 63. Electric motor 111 isinitially turned on to drive trocar 47 when switch 117 is turned on.However, when trocar 63 moves a distance sufficient to disengage raisedstrip 119 from switch button 121, first switch 118 turns off anddisconnects power from motor 111. Removing power by turning switch 118off, also stops or limits the movement of trocar and obdurator assembly63. Motor 111 is preferably powered by battery 122, although other powersources consistent with the operating room environment and the patientssafety may be used.

FIG. 19 shows a more sophisticated trocar distance limiting meanscomprising a sonic transceiver or transducer 126 for transmitting sonicwaves 127 into abdominal wall 24 and for receiving reflection signals128 of the transmitted waves 127. Separate transmitter and receiverdevices for the sonic waves may alternatively be used. One or morepiezoelectric transducers may be used for transmitting and/or detectingthe sonic waves, or other devices known in the art may be used.

A sonic wave frequency (or frequencies) may be selected from a broadrange frequencies to detect the boundary between the abdominal walltissues and a void (or gas filled) body cavity region. The boundary isdetected by sensing a sharp change in the sonic wave reflectancecharacteristics as illustrated in FIG. 20. The broad frequency range issuitable because of the great mismatch in acoustic impedance between avoid (or gas filled) region, and a region of tissue (which has arelatively high water content). For example, sonic waves having acousticfrequencies between about 2 megahertz and about 12 megahertz may beused. These are the same frequencies commonly used in clinical acousticimaging of the body. Somewhat higher or lower frequencies may alsoprovide adequate boundary detection.

Sonic transceiver 126 may be removably located within obdurator 64itself, such as within recess 129 at one end of obdurator 64, or thesonic waves may be directed through obdurator 64 by a more remote sonictransceiver. It is important however, that the reflected waves, orprocessed versions thereof, indicate the location of obdurator tip 105so that motion can be arrested before the obdurator tip pierces toodeeply into abdominal cavity 28.

Signal analysis means for analyzing the reflection signals 128 and fordetermining when obdurator 64 traverses abdominal wall 24 and,penetrates abdominal cavity 28 are also provided as illustrated in FIG.21. Signal analysis means may comprise a simple electrical circuit 131,such as those that detect a threshold crossing, or that detect a signalphase change related to the transition, for example, or may comprisemore sophisticated processing such as circuits incorporating amicroprocessor with appropriate software or firmware algorithms.

Switch 117 for turning motor 111 off is interfaced to signal analysismeans 131 and is responsive to signals from signal analysis means 131 toturn off motor 111 when obturator 64 has penetrated abdominal cavity 28.For example, when the signal analysis means 131 determines that theboundary between tissue and the void cavity has been reached, it cutspower to the trocar motor to stop penetration. In this way, the risk ofobdurator tip 105 piercing any internal organs is diminished. Motor 111,switch 118, switch 117, signal analysis means 131, and any requiredpower supplies are interfaced as is known in the art. A singleintegrated battery powered unit having the transducer and signalanalysis means on board the trocar is preferred; however, if desiredseparate components, including the signal analysis means 131, may beprovided remote from trocar applicator 62.

The trocar system 21 including rack 23 and trocar device 22 operates andis used as follows. Patient 27 is placed on supporting platform 48 priorto the surgical procedure. Cross beams 31 are adjustably positioned tospan the external abdominal region 44 yet provide access to the trocarinsertion site(s), and lowered by vertical supports 32 so that tapesurface 41 applied to skin 42 is adhered to attaching arm 37. Crossbeams 31 are then raised to separate abdominal wall 24 from abdominalviscera 26 and open a void space in the abdominal cavity 28. If desired,after making the appropriate incision, L-shaped rods 50 attached tocross beams 31 may optionally be used to aid in lifting and/ormaintaining the separation. The patient is now ready for insertion of atrocar 22.

The approximate tissue depth 132 between the exterior abdominal skin 42and the inner surface of the parietal peritoneum 43, is determined. Thetissue depth 132 may be determined based on external physicalcharacteristics of patient 27, or determined using other conventionaltechniques, such as ultra-sound measurements, for example.

Trocar device 22 (which is maintained in a sterile condition) isprepared by setting slip-ring 91 at the appropriate location withincoarse threads 88 to set the penetration depth to allow the trocar toextend beyond the tissue depth 132. Trocar device 22 is then placed overthe insertion site and held in place while trigger 67 is releasedcausing spring 66 to drive trocar obdurator 64 into abdominal cavity 28.Obdurator 63 is then removed from within trocar tube 47. Applicator 62is then removed from around trocar tube 47 by opening the clam-shelltype housing 65 along hinge 82. Trocar mounting arm 51 is used formounting trocar 47 to cross-beam 31 to maintain trocar tube 47 in astable upright position. A surgical instrument may then be inserted andlater removed through trocar tube 47.

In the embodiments having electric motor 111 rather than spring 66 todrive trocar-obdurator assembly 63, the operation is substantially thesame except that the force means is triggered to drive thetrocar-obdurator assembly into the abdomen by supplying electrical powerto the motor and the penetration depth is limited by disconnect powerform the motor.

In the embodiment having a sonic transceiver, the operation issubstantially the same except that switch 117 for turning motor 111 offis responsive to signals from signal analysis means 131 and turns offmotor 111 when the received reflection signals indicate that obdurator64 has penetrated abdominal cavity 28.

It is evident from the above description, that a convenient low costtrocar system and method for using is provided which allows the user tosafely raise the abdominal wall away from the viscera and to insert atrocar into the abdominal cavity of a patient.

The trocar surgical rack system advantageously provides for safeinsertion of gas valve free trocars without insufflation of theabdominal cavity, and may also be used during insertion of conventionalgas-valve type trocars. The rack system also advantageously holds aninserted trocar device upright after insertion, even with a surgicalinstrument in place, preventing the undesirable leaning that is oftenassociated with conventional trocars. The number of trocars which may beused simultaneously is also increased, because the rack holds themstably in position and they do not require significant attention fromsurgical staff during the surgical procedure.

The trocar device according to the present invention advantageouslyprovides a trocar that has an adjustable penetration depth for safety.The trocar device is also gas valve free so that the cost of each trocaris significantly reduced compared to gas-valve type trocars. Valve-freedesign also increases compatibility with a potentially larger set ofsurgical instruments since such instruments need not be compatible witha trocar valve. The low cost also permits disposal of each trocar aftera single use when desired.

Although the foregoing invention has been described in some detail byway of illustration and example for purposes of clarity ofunderstanding, it will be readily apparent to those of ordinary skill inthe art in light of the teachings of this invention that certain changesand modifications may be made thereto without departing from the spiritor scope of the appended claims and their equivalents.

All publications and patent applications cited in this specification areherein incorporated by reference as if each individual publication orpatent application were specifically and individually indicated to beincorporated by reference.

What is claimed is:
 1. A method for inserting a trocar into an internalbody cavity through both the exterior and interior body wall surfaces ofa patient without insufflation of said internal body cavity, said methodcomprising the steps of:attaching the external skin surface adjacentsaid internal body cavity to a movable support disposed external to saidbody wall and body cavity; lifting said movable support away from saidinternal body cavity to open a void between said body wall and internalbody structures within said body cavity; and inserting said trocarthrough said body wall into said void space.
 2. The method in claim 1,wherein said method further comprises the step of fastening said trocarto said movable support external to said body cavity to support saidtrocar in a stable orientation.
 3. The method in claim 1, wherein saidmethod further comprises the steps of:inserting at least one rod havingan L-shaped cross-section from a location external to said body wallinto said body cavity to engage said interior surface of said body wall;and moving said or each engaged rod away from said internal bodystructures in a direction toward said exterior body wall surface toseparate said body wall from said internal body structures and to open avoid space between said body wall and said internal body structures. 4.The method in claim 3, wherein said step of inserting said or each rodinto said body cavity comprises the steps of:providing a rod apparatushaving conformation adjustable between a first substantially linearconformation and a second L-shaped conformation; adjusting said rodapparatus into said first linear conformation; inserting said rodapparatus while in said linear conformation through said body wall ofsaid patient into said body cavity; and adjusting said rod apparatusafter said insertion into said second L-shaped conformation to providean L-shaped rod having a relatively longer linear portion extendingthrough said body wall and a relatively shorter portion extending at anangle from said linear portion located internal to said body cavity. 5.The method in claim 4, wherein said skin is the skin at the exteriorsurface of the patients abdomen, body wall is the abdominal wall,wherein said body cavity is the abdominal cavity, and wherein saidinternal body structures are abdominal viscera.
 6. A method forinserting a trocar into a body cavity through the body wall of a patientwithout insufflation of said body cavity, said method comprising thesteps of:attaching the skin adjacent said body cavity to a movablesupport; lifting said movable support away from said body cavity to opena void between said body wall and internal body structures within saidbody cavity; and inserting said trocar through said body wall into saidvoid space fastening said trocar to said movable support to support saidtrocar in a stable and substantially upright orientation; wherein saidtrocar comprises a trocar applicator for applying a trocar to piercesaid abdominal wall and a trocar and obdurator assembly for extendingthrough said abdominal wall adapted for use with said trocar applicator;said trocar applicator including:a housing including a lower pad havinga orifice through which said trocar can extend and a vertical framemounted on said pad; force means for driving said trocar through saidabdominal wall mounted in said frame distal from said pad; means formaintaining said force means in a deactivated position and foractivating said force means to drive said trocar; and at a positionintermediate between said pad and said force means attached to saidvertical frame, trocar limiting means for limiting the distance saidtrocar is driven through said abdominal wall; said trocar and obduratorassembly including:a cylindrical trocar tube; trocar stopping means forcooperating with said trocar limiting means for limiting the distancesaid trocar is driven through said abdominal wall; an obduratorextending through said cylindrical tube and having a sharp end capableof extending past one of said ends of said cylindrical tube; and meansfor locking said obdurator into position in said tube; and wherein saidmovable support includes:a horizontal rack; spaced apart horizontalcross-beams supported by said horizontal rack; vertical supporting meansfor raising and lowering said horizontal rack with synchronous movementof said cross-beams; and attaching means extending downwardly from eachof said cross-beams for attaching to a tape surface; and wherein saidstep of attaching said skin adjacent said body cavity to a movablesupport comprises the step of attaching said skin to said downwardlyextending attaching means; and wherein said step of inserting saidtrocar through said body wall comprises the steps of activating, aftersaid step of lifting to open a void, said force means for driving saidtrocar to drive said trocar through said abdominal wall into said void;and limiting the distance said obdurator of said trocar and obduratorassembly is driven by said force means of said trocar applicator throughsaid abdominal wall.
 7. The method in claim 1, wherein said step ofinserting said trocar comprises inserting a gas-valve-free trocarwithout insufflation of said internal body cavity.
 8. The method inclaim 1, wherein said movable support includes a gripping surface forgripping said external skin surface, and wherein said step of attachingsaid external skin surface to said movable support comprises grippingsaid external skin surface.
 9. The method in claim 1, wherein saidmovable support includes an adhesive surface for adhesively attachingsaid external skin surface to said movable support, and wherein saidstep of attaching said external skin surface to said movable supportcomprises adhering said external skin surface to said movable support.10. The method in claim 9, wherein said adhesive surface comprises anadhesive tape surface.
 11. The method in claim 3, wherein said steps ofinserting said or each rod, and moving said or each engaged rod awayfrom said internal body structures to open a void space, are performedbefore said step of inserting said trocar through said body wall intosaid void space;said step of inserting said or each rod comprisesinserting said or each rod through a separate rod incisions at differentlocations on said skin surface; and said step of inserting said trocarcomprises inserting said trocar through said body wall at a locationdifferent from the insertion location of said or each rod.
 12. Themethod in claim 3, wherein said rod having an L-shaped cross-sectioncomprises an L-shaped rod having a relatively longer first linearportion and a relatively shorter second portion extending at an anglefrom said first linear portion.
 13. The method in claim 12, wherein saidangle is about 90 degrees.
 14. The method in claim 3, Wherein said rodhaving an L-shaped cross-section comprises a T-shaped rod having twoL-shaped cross-sections.
 15. The method in claim 3, wherein said rodhaving an L-shaped cross-section comprises a fan-shaped rod having aplurality of L-shaped cross-sections.
 16. The method in claim 1, furthercomprising the step of limiting a distance of insertion of said trocarto a predetermined distance that is less than the distance to saidinternal body structures.
 17. A method for inserting a gas-valve-freetrocar apparatus into an internal body cavity through the external bodywall of a patient without insufflation of said body cavity and withoutpuncturing structures internal to said body cavity, said methodcomprising the steps of:attaching the external skin adjacent said bodycavity to a movable support disposed at a first location external tosaid body wall and body cavity; moving said movable support away fromsaid internal structures within said body cavity to open a void spacebetween said internal body wall and said internal structures; attachinga trocar applicator having a housing including a pad having a orificethrough which said gas-valve-free trocar can extend and a vertical framemounted on said pad, and a spring for driving said trocar through saidorifice and said body wall mounted in said frame; and trigger means forcontrolling said driving of said trocar by said spring; inserting saidgas-valve-free trocar assembly having a trocar tip and an obdurator withsaid applicator to pierce said body wall at a second location differentfrom said first skin attachment location into said void space withoutinsufflating said body cavity; fastening said trocar to said movablesupport to support said trocar in a stable position; said step of movingsaid movable support to open a void space is performed before said stepof inserting said trocar through said body wall into said void space;wherein said movable support includes: a rack, spaced apart horizontalcross-beams supported by said rack, vertical supports for moving saidrack selectively toward and away from said patient with synchronousmovement of said cross-beams, and attaching means extending toward saidpatient from each of said cross-beams for attaching to a tape surface;and wherein said step of attaching said skin to said movable supportcomprises attaching said skin to said extending attaching means.